IT IS the best kept secret in showbusiness and it has got gossip columnists in a whirl of speculation.

IT IS the best kept secret in showbusiness and it has got gossip columnists in a whirl of speculation. Where and when are Sir Paul McCartney and Heather Mills to marry?

The singer has said the marriage will take place this summer, but has kept the ceremony shrouded in mystery in an effort to escape the prying eyes of the Press on the couple's big day.

Castle Leslie in Co Monaghan, Ireland, on June 11, is the latest prediction from veteran New York Post gossip columnist Cindy Adams.

But the report contradicts a columnist in her own newspaper, Neal Travis, who reports it is going to be on Thursday, or maybe this weekend, in the Hampton's on New York's Long Island.

Travis, who lives in the area, reported that it would be at the Hampton's home of John Eastman, the brother of Sir Paul's late wife, Linda.

Other reports said the ceremony will be somewhere in Ireland, but only after the couple have led guests on a "marital mystery tour", keeping them in the dark about the exact location until the very last minute.

There was also speculation the marriage would take place at Skibo Castle in Scotland, where Madonna and Guy Ritchie had their wedding reception last year, or at a secret location in England.

For his part, Sir Paul has said only that wedding preparations are "going fine".

Even his official spokesman insists he does not know where it will be - and that he prefers it that way.

Sir Paul, 59, met Miss Mills, 34, three years ago and they became engaged last July.

Miss Mills made her name as a campaigner for the disabled after she lost a leg when she was hit by a police motorcycle in 1993.